SQL query to display data in gridview

I have a grid view that displays data from a SQL Server database during page load. My gridview contains these columns:

AssetType, IssuedOn, ReturnedOn

I have used a query:

SqlCommand cmd = new SqlCommand(
    "SELECT * FROM AssetRequest WHERE ReturnedOn IS NULL OR ReturnedOn ='' ORDER BY id DESC",
    conn);

which will display data from SQL Server in the gridview when ReturnedOn column doesn’t have any data.

The new query has to satisfy these conditions,

1. It Should not displays a record when Assetype=”Laptop” or “Desktop” and IssuedOn is not empty.
2. But if the Assetype=”Laptop” or “Desktop” and IssuedOn is empty it should display the record.
3. If the Assetype=anything and Returnedon is not empty it should not display that record in gridview.

Answer

I hope this query resolves your issue.

SELECT *
FROM AssetRequest
WHERE (AssetType IN ('Laptop', 'Desktop') AND (IssuedOn IS NULL OR IssuedOn = '') AND (ReturnedOn IS NULL OR ReturnedOn = '')) 
OR (AssetType NOT IN ('Laptop', 'Desktop') AND (ReturnedOn IS NULL OR ReturnedOn = ''))